Tube-in-tube heat exchanger

Abstract

The utility model discloses a sleeve type heat exchanger which comprises a low-temperature fluid inlet header, a low-temperature fluid outlet header, a hot fluid inlet header and a hot fluid outlet header, a plurality of hot fluid outlets are formed in the hot fluid inlet header, and U-shaped or snake-shaped hot fluid pipes are arranged at the hot fluid outlets. A plurality of hot fluid inlets which are in butt joint with the hot fluid pipes one by one are formed in the hot fluid inlet header, and the outer sides of the hot fluid pipes are sleeved with outer sleeves in a sealed mode; the distance between the vertex of the outer bending part of the U-shaped part of the hot fluid pipe and the inner wall of the outer sleeve is greater than the difference of expansion of the hot fluid pipe when heated during heat exchange; a plurality of low-temperature fluid output ports are formed in the low-temperature fluid inlet header, low-temperature fluid inlets are formed in the outer sleeve, output flow guide pipes are arranged between the low-temperature fluid output ports and the corresponding low-temperature fluid inlets, and low-temperature fluid outlets are formed in the end, close to the hot fluid inlet header, of the outer sleeve. A plurality of low-temperature fluid backflow openings are formed in the low-temperature fluid outlet collecting box, and a backflow flow guide pipe is arranged at the low-temperature fluid outlet.

Description

Technical Field

[0001] The utility model relates to a heat exchange device, in particular to a shell-and-tube heat exchanger. Background Art

[0002] At present, the steam-steam heat exchangers (using high-temperature superheated steam to heat low-temperature reheated steam in boiler equipment) and the high and low pressure heaters for heating condensate in the steam turbine condensate heating system, which are commonly used in the power industry, are complex in structure and manufacturing process, consume a large amount of steel, and have high machining costs; and leakage is a common defect, especially in the high-pressure return water part of the high-pressure heater in the steam turbine return water system, and the steam-steam heat exchanger in the boiler equipment also has similar problems.

[0003] For example, the heat exchanger disclosed in the patent application 202311594027.3, a heat exchange device and its preparation method, a large number of heat exchange fins are not only easy to damage, but also increase the equipment volume, and the contact between the low-temperature liquid and the heat source is not sufficient, resulting in low heat exchange efficiency. Content of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a shell-and-tube heat exchanger with high heat exchange efficiency.

[0005] To solve the above technical problem, the technical solution adopted by the utility model is: a shell-and-tube heat exchanger, including a low-temperature fluid inlet header, a low-temperature fluid outlet header, a hot fluid inlet header, and a hot fluid outlet header. There are several hot fluid outlets on the hot fluid inlet header. At the hot fluid outlet, there is a U-shaped or serpentine hot fluid tube. There are several hot fluid inlets on the hot fluid inlet header that are in one-to-one connection with each hot fluid tube. The outer side of the hot fluid tube is hermetically sleeved with an outer tube as the channel for the low-temperature fluid; the distance between the vertex of the outer bending part of the U-shaped or serpentine part of the hot fluid tube and the inner wall of the outer tube is greater than the expansion difference when the hot fluid tube exchanges heat with the cold fluid and expands due to heat.

[0006] There are several low-temperature fluid output ports on the low-temperature fluid inlet header. There is a low-temperature fluid inlet at the end of the outer tube close to the hot fluid outlet header. There is an output diversion tube between the low-temperature fluid output port and the corresponding low-temperature fluid inlet. There is a low-temperature fluid outlet at the end of the outer tube close to the hot fluid inlet header. There are several low-temperature fluid return ports on the low-temperature fluid outlet header that are in one-to-one correspondence with each outer tube. There is a return diversion tube between the low-temperature fluid outlet and the corresponding low-temperature fluid return port.

[0007] As a preferred solution, several low-temperature fluid outlets provided on the low-temperature fluid inlet header include a first low-temperature fluid outlet and a second low-temperature fluid outlet which are arranged at intervals. The first low-temperature fluid outlet is arranged at the bottom of the low-temperature fluid inlet header, and the second low-temperature fluid outlet is arranged on the side part of the low-temperature fluid inlet header close to the bottom.

[0008] As a preferred solution, several low-temperature fluid return ports provided on the low-temperature fluid outlet header include a first low-temperature fluid return port and a second low-temperature fluid return port which are arranged at intervals. The first low-temperature fluid return port is arranged at the bottom of the low-temperature fluid outlet header, and the second low-temperature fluid return port is arranged on the side part of the low-temperature fluid outlet header close to the bottom.

[0009] As a preferred solution, the outer sleeve includes outer straight pipes sleeved on two straight pipe sections of the hot fluid pipe and a heat exchange elbow section welded to connect the two outer straight pipes. Sealing end plates are provided at the ends of the outer straight pipes, and the elbow section includes two semi-circular elbows welded together.

[0010] As a preferred solution, threads are provided on the outer periphery of the hot fluid pipe.

[0011] As a preferred solution, the hot fluid pipe includes two straight pipe sections and a U-shaped or serpentine hot fluid elbow section welded between the two straight pipe sections. The welding parts of the outer sleeve are arranged in a staggered manner with the welding parts connecting the outer straight pipes and the heat exchange elbow section.

[0012] As a preferred solution, the two semi-circular elbows are symmetrically arranged.

[0013] The beneficial effects of the present utility model are as follows:

[0014] Due to the use of the U-shaped or serpentine sleeve for heat exchange, the low-temperature fluid contacts the hot fluid pipe more fully, the heat exchange efficiency is higher, and the overall structure is more compact. In addition, since the distance between the vertex of the outer bending part of the U-shaped or serpentine part of the hot fluid pipe and the inner wall of the outer sleeve is greater than the expansion difference of the hot fluid pipe during heat exchange; the safety during the use of the equipment is ensured.

[0015] Since several low-temperature fluid outlets provided on the low-temperature fluid inlet header include a first low-temperature fluid outlet and a second low-temperature fluid outlet which are arranged at intervals. The first low-temperature fluid outlet is arranged at the bottom of the low-temperature fluid inlet header, and the second low-temperature fluid outlet is arranged on the side part of the low-temperature fluid inlet header close to the bottom; it is convenient for the installation of the outlet guide pipe and also ensures the strength of the low-temperature fluid inlet header.

[0016] Since several low-temperature fluid return ports provided on the low-temperature fluid outlet header include a first low-temperature fluid return port and a second low-temperature fluid return port that are spaced apart, the first low-temperature fluid return port is provided at the bottom of the low-temperature fluid outlet header, and the second low-temperature fluid return port is provided on the side portion of the low-temperature fluid outlet header near the bottom; it facilitates the installation of the return guide pipe and also ensures the strength of the low-temperature fluid outlet header.

[0017] Since the outer sleeve includes outer straight pipes sleeved on two straight pipe sections of the hot fluid pipe and a heat exchange elbow section welded to connect the two outer straight pipes, sealing end plates are provided at the ends of the outer straight pipes, and the elbow section includes two semi-circular elbows welded together, making the outer sleeve easy to process and manufacture, and in use, the structure is stable and not easily damaged.

[0018] Since threads are provided on the outer periphery of the hot fluid pipe, the disturbance is strengthened when the low-temperature liquid longitudinally flushes its surface, thereby improving the heat exchange effect.

[0019] Since the hot fluid pipe includes two straight pipe sections and a U-shaped or serpentine hot fluid elbow section welded between the two straight pipe sections, the welding parts of the outer sleeve are arranged in a staggered manner with the welding parts connecting the outer straight pipes and the heat exchange elbow section, avoiding the influence of the heat generated during the welding of the outer sleeve on the welding parts of the hot fluid pipe and ensuring the reliability of the seams of the hot fluid pipe.

[0020] Since the two semi-circular elbows are symmetrically arranged, the stress of the weld seam is more uniform, thereby further ensuring the reliability of the equipment during use. Brief Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the present sleeve-type heat exchanger.

[0022] Figure 2 is Figure 1 the A-A sectional structural diagram of

[0023] Figure 3 is a schematic structural diagram of the hot fluid pipe and the outer sleeve part.

[0024] Figure 4 is Figure 3 the sectional view of

[0025] In the figure: 1 low-temperature fluid inlet header, 2 low-temperature fluid outlet header, 3 hot fluid inlet header, 4 hot fluid outlet header, 5 hot fluid pipe, 6 outer sleeve; 7 output guide pipe, 8 return guide pipe. Detailed Embodiment

[0026] The following will describe in detail the specific implementation scheme of the present utility model in conjunction with the drawings.

[0027] As Figures 1-4As shown in the figure, a shell-and-tube heat exchanger includes a low-temperature fluid inlet header 1, a low-temperature fluid outlet header 2, a hot fluid inlet header 3, and a hot fluid outlet header 4. The hot fluid inlet header 3 is provided with a number of hot fluid outlets, and at the hot fluid outlets, there are U-shaped or serpentine hot fluid tubes 5, and the outer periphery of the hot fluid tubes 5 is provided with threads. The hot fluid inlet header 3 is provided with a number of hot fluid inlets that are respectively connected to each of the hot fluid tubes 5 one by one. The outer side of the hot fluid tube 5 is hermetically sleeved with an outer sleeve 6 as the channel for the low-temperature fluid; the distance (the part marked L in the attached drawing) between the vertex of the bent part on the outer side of the U-shaped or serpentine part of the hot fluid tube 5 and the inner wall of the outer sleeve 6 is greater than the expansion difference when the hot fluid tube 5 exchanges heat with the cold fluid and expands due to heat.

[0028] The low-temperature fluid inlet header 1 is provided with a number of low-temperature fluid outlets, and at the end of the outer sleeve 6 near the hot fluid outlet header 4, there is a low-temperature fluid inlet. Between the corresponding low-temperature fluid outlet and the low-temperature fluid inlet, there is an output diversion pipe 7. At the end of the outer sleeve 6 near the hot fluid inlet header 3, there is a low-temperature fluid outlet. The low-temperature fluid outlet header 2 is provided with a number of low-temperature fluid return ports that are respectively connected to each of the outer sleeves 6 one by one. Between the low-temperature fluid outlet and the corresponding low-temperature fluid return port, there is a return diversion pipe 8.

[0029] The number of low-temperature fluid outlets provided on the low-temperature fluid inlet header 1 includes a first low-temperature fluid outlet and a second low-temperature fluid outlet that are arranged at intervals. The first low-temperature fluid outlet is arranged at the bottom of the low-temperature fluid inlet header 1, and the second low-temperature fluid outlet is arranged on the side part of the low-temperature fluid inlet header 1 near the bottom.

[0030] The number of low-temperature fluid return ports provided on the low-temperature fluid outlet header 2 includes a first low-temperature fluid return port and a second low-temperature fluid return port that are arranged at intervals. The first low-temperature fluid return port is arranged at the bottom of the low-temperature fluid outlet header 2, and the second low-temperature fluid return port is arranged on the side part of the low-temperature fluid outlet header 2 near the bottom.

[0031] The outer sleeve 6 includes outer straight pipes sleeved on two straight pipe sections of the hot fluid tube 5, and a heat exchange elbow section that welds and connects the two outer straight pipes. The end of the outer straight pipe is provided with a sealing end plate. The elbow section includes two semi-circular elbow pipes that are welded together in an opposing manner. The two semi-circular elbow pipes are symmetrically arranged.

[0032] The hot fluid tube 5 includes two straight pipe sections and a U-shaped or serpentine hot fluid elbow section welded between the two straight pipe sections. The welding part of the outer sleeve 6 is arranged in a dislocation manner with the welding part where the outer straight pipe and the heat exchange elbow section are connected.

[0033] It should be noted that the channels for the low-temperature (high-temperature) fluid in this heat exchanger can also be used for high-temperature (low-temperature) fluid according to actual applications.

[0034] Using this heat exchanger as the heater for the steam turbine return water system and the steam-steam heat exchanger for the boiler steam system can save 30% of the material amount compared with the existing structure, and the processing and manufacturing process is simple, which can greatly reduce the cost.

[0035] The above embodiments are only illustrative of the principles and effects of the present invention and some embodiments of its application, rather than limiting the present utility model; it should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present utility model.

Claims

1. A shell-and-tube heat exchanger, comprising a cryogenic fluid inlet header, a cryogenic fluid outlet header, a hot fluid inlet header, and a hot fluid outlet header, wherein the hot fluid inlet header is provided with a plurality of hot fluid outlets, characterized in that : The hot fluid outlet is provided with a U-shaped or serpentine hot fluid pipe, the hot fluid inlet header is provided with a plurality of hot fluid inlets connected to the hot fluid pipes one by one, and the outer sealing sleeve of the hot fluid pipe is provided with an outer sleeve as a passage for the low-temperature fluid; the distance between the vertex of the outer bending part of the U-shaped or serpentine part of the hot fluid pipe and the inner wall of the outer sleeve is greater than the expansion difference of the hot fluid pipe when exchanging heat with the cold fluid; A plurality of cryogenic fluid output ports are arranged on the cryogenic fluid inlet manifold, a cryogenic fluid inlet is arranged at the end of the outer sleeve close to the hot fluid outlet manifold, an output guide pipe is arranged between the cryogenic fluid output port and the corresponding cryogenic fluid inlet, a cryogenic fluid outlet is arranged at the end of the outer sleeve close to the hot fluid inlet manifold, a plurality of cryogenic fluid return ports corresponding to each outer sleeve are arranged on the cryogenic fluid outlet manifold, and a return guide pipe is arranged between the cryogenic fluid outlet and the corresponding cryogenic fluid return port.

2. A double-tube heat exchanger according to claim 1, characterized in that: The plurality of cryogenic fluid outlets provided on the cryogenic fluid inlet manifold include a first cryogenic fluid outlet and a second cryogenic fluid outlet which are arranged at intervals. The first cryogenic fluid outlet is provided at the bottom of the cryogenic fluid inlet manifold, and the second cryogenic fluid outlet is provided on a side portion of the cryogenic fluid inlet manifold close to the bottom.

3. A double-tube heat exchanger according to claim 2, characterized in that: The plurality of low-temperature fluid return ports arranged on the low-temperature fluid outlet manifold include a first low-temperature fluid return port and a second low-temperature fluid return port arranged at intervals. The first low-temperature fluid return port is arranged at the bottom of the low-temperature fluid outlet manifold, and the second low-temperature fluid return port is arranged on the side portion of the low-temperature fluid outlet manifold close to the bottom.

4. A double-tube heat exchanger according to claim 2, characterized in that: The outer sleeve includes an outer straight tube sleeved on two straight tube sections of the hot fluid tube, and a heat exchange bent tube section welded to the two outer straight tubes. The ends of the outer straight tubes are provided with sealing end plates, and the bent tube section includes two semi-arc bent tubes welded together.

5. A double-tube heat exchanger according to claim 1, characterized in that: The outer circumference of the thermal fluid pipe is provided with threads.

6. A double-tube heat exchanger according to claim 1, characterized in that: The thermal fluid pipe comprises two straight pipe sections and a U-shaped or serpentine thermal fluid bend pipe section welded between the two straight pipe sections. The welding portion of the outer sleeve is staggered with the welding portion connecting the outer straight pipe and the heat exchange bend pipe section.

7. A double-tube heat exchanger according to claim 4, characterized in that: The two semi-arc bent pipes are symmetrically arranged.

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